Young infants' exposure to parabens: lotion use as a potential source of exposure

Parabens are widely used as antimicrobials in personal care products and pharmaceuticals. While previous studies demonstrate paraben exposure is ubiquitous, data investigating infants' exposure is limited.

We sought to characterize infants' exposure to parabens and identify factors associated with higher levels of exposure.

Families enrolled in the CHildren's Immune ResPonse Study between 2016-2018. Parents completed questionnaires, providing information on demographics and lifestyle factors. Urine samples were collected when infants were 1 to 3 months old (n = 71) and 12 months old (n = 29), with 18 infants evaluated at both ages. Parabens were measured in urine samples using liquid chromatography tandem mass spectrometry and served as an indicator of exposure.

Methylparaben (MP), ethylparaben (EP), and propylparaben (PP) were detected in >70% of urine samples, and concentrations ranged several orders of magnitude (specific-gravity-corrected medians: MP = 25.4 PP = 3.55; EP = 0.90 ng/mL). Butylparaben was detected less frequently (<50%). Paraben concentrations were lower than those reported for older children and adults; however, we did not find statistically significant differences in paraben concentrations by infant age. Correlations between measurements taken over time were poor, suggesting paraben exposure is variable, and multiple measurements are needed to capture cumulative exposure information. We observed differences in exposure by race/ethnicity and socioeconomic status; non-White infants and infants whose parents completed less education had higher paraben exposure. Recent lotion usage strongly predicted paraben exposure in 1-3-month-olds. For example, infants using lotion in the past seven days had urinary MP concentrations 355% higher than infants without lotion usage (e^ß = 4.55, 95% Confidence Interval = 1.68, 12.55, p < 0.001). Together, our results suggest infants are ubiquitously exposed to parabens and personal care product use may be an important source of exposure.

To the best of our knowledge, this is the first paper to report paraben levels and evaluate predictors of exposure in infants. This study supports the hypothesis that universal exposure to parabens extends to infants, as indicated by urinary biomarker concentrations. Of the predictors evaluated, lotion use in the last seven days was the strongest predictor of exposure in 1-3-month-olds. Given infant paraben levels are strongly correlated to lotion use, there may be an opportunity for parents to reduce paraben exposure by limiting its application or consulting ingredient labels to ensure no parabens are present.